egg yolk and butter into a large bowl and mix together until combined to a smooth dough.
With lightly floured hands
break off evenly sized pieces of the dough and roll into walnut sized balls.
Place the dough balls onto a baking sheet lined with silicon paper or baking parchment and gently press each ball with the back of a fork to flatten slightly.
Place in the oven and bake for ten minutes
or until just turning golden-brown.
Transfer the cookies to a wire rack and allow to cool for ten minutes.
To serve
place on a serving plate and dust with icing sugar.
